The research is part of a broader scientific effort to explore the microbiome, the trillions of microbes — bacteria, viruses and fungi — that colonize the human body, inside and out. Those organisms affect digestion, metabolism and an unknown array of biological processes, and may play a role in the development of obesity, diabetes and other illnesses.
During pregnancy, the authors of the new study suspect, the wrong mix of bacteria in the placenta may contribute to premature births, a devastating problem worldwide. Although the research is preliminary, it may help explain why periodontal disease and urinary infections in pregnant women are linked to an increased risk of premature birth. The findings also suggest a need for more studies on the effects of antibiotics taken during pregnancy.
The new study suggests that babies may acquire an important part of their normal gut bacteria from the placenta. If further research confirms the findings, that may be reassuring news for women who have had cesareans. Some researchers have suggested that babies born by cesarean miss out on helpful bacteria that they would normally be exposed to in the birth canal.
"I think women can be reassured that they have not doomed their infant's microbiome for the rest of its life," said Dr. Kjersti Aagaard, the first author of the new study, published on Wednesday in Science Translational Medicine. She added that studies were needed to determine the influence of cesareans on the microbiome.
Previous studies have looked at bacteria that inhabit the mouth, skin, vagina and intestines. But only recently has attention turned to the placenta, a one-pound organ that forms inside the uterus and acts as a life support system for the fetus. It provides oxygen and nutrients, removes wastes and secretes hormones.
"People are intrigued by the role of the placenta," said Dr. Aagaard, an associate professor of obstetrics and gynecology at the Baylor College of Medicine and Texas Children's Hospital in Houston. "There's no other time in life that we acquire a totally new organ. And then we get rid of it."
Image: Healthy baby, via Shutterstock